Car frame featuring rtm-technology modules of compsite material

ABSTRACT

A car frame having a central body, which defines the passenger compartment of the car and is defined by a number of metal parts welded to one another. A monolithic front body is bolted to the central body and is made of composite material fibre using RTM technology. A monolithic floor panel is also connected to the central body and is made of composite material fibre using RTM technology.

TECHNICAL FIELD

The present invention relates to a car frame.

BACKGROUND ART

A mass-produced car frame is normally made of metal (steel or aluminium). To improve the mechanical characteristics and reduce the weight of racing cars, frames made of composite material (typically carbon or Kevlar) fibre have been introduced, the commonest of which substantially comprises a single monolithic body made of hand-laminated carbon and/or Kevlar fibre.

A mass-produced car frame of composite material normally comprises a central body defining the passenger compartment, made of hand-laminated carbon and/or Kevlar fibre, and to which are bolted a front and rear body also made of hand-laminated carbon and/or Kevlar fibre. This solution is selected to simplify and reduce the cost of repairing the car in the event of an accident. Composite materials, in fact, are difficult to repair, especially in other than specialized workshops, and, when damaged, are preferably replaced. An example of a car frame made entirely of composite material is described in Patent Application GB-2317858-A.

Frames made of composite material fibre have better mechanical characteristics and are lighter than metal frames, but are much more expensive and take much longer to produce. Which is why, in the case of road vehicles, composite material fibre frames are currently limited to high-performance cars produced in very small numbers (at most one or two cars a day).

In the case of mass-produced vehicles, only single parts made of composite material fibre have so far been proposed, as described for example in Patent Application EP-1316409-A1, which relates to a truncated-cone-shaped insert for gradually absorbing the energy of a head-on collision. Another example of a car featuring a front insert of composite material for gradually absorbing the energy of a head-on collision is described in U.S. Pat. No. 6,698,822-B1.

DISCLOSURE OF INVENTION

It is an object of the present invention to provide a car frame which is cheap and easy to produce, while at the same time eliminating the aforementioned drawbacks.

According to the present invention, there is provided a car frame as recited in the accompanying Claims.

BRIEF DESCRIPTION OF THE DRAWINGS

A non-limiting embodiment of the present invention will be described by way of example with reference to the accompanying drawings, in which:

FIG. 1 shows a schematic view in perspective of a frame in accordance with the present invention;

FIGS. 2 and 3 show two larger-scale views in perspective of a front body of the FIG. 1 frame;

FIG. 4 shows a view in perspective of a floor panel of the FIG. 1 frame.

BEST MODE FOR CARRYING OUT THE INVENTION

Number 1 in FIG. 1 indicates a car frame comprising a central body 2 defining the passenger compartment of the car. Central body 2 is made of aluminium by welding together a number of component parts, and in particular comprises a number of extruded, constant-section, straight bars 3 welded to one another at structural nodes defined by connecting bodies 4. Each connecting body 4 comprises a number of pockets (not shown in detail) for housing the ends of corresponding straight bars 3. More specifically, four connecting bodies 4 (two front connecting bodies 4 and two rear connecting bodies 4) are provided at the suspension attachment points.

A front body 5 and a floor panel 6, both made of composite material fibre using RTM (Resin Transfer Molding) technology, are bolted to central body 2, and may be made of carbon fibre, Kevlar fibre, or a mixture of carbon/Kevlar fibre and glass fibre. Glass fibre is obviously used to reduce manufacturing cost, compatibly with the desired structural characteristics.

As shown in FIG. 2, front body 5 is monolithic, and comprises a front panel 7 positioned crosswise to frame 1 and from which extend upwards two lateral panels 8 positioned longitudinally with respect to frame 1. Lateral panels 8 are positioned with their ends resting against central body 2, which preferably comprises a number of seats 9 into which the ends of respective end portions of lateral panels 8 fit. The end portions of lateral panels 8 have a number of through holes (not shown in detail) through which respective screws (not shown in detail) are inserted and fixed to central body 2. More specifically, lateral panels 8 are positioned with their ends resting against two front connecting bodies 4 of central body 2, i.e. the two connecting bodies 4 at the front suspension attachment points, which connecting bodies 4 have seats 9.

As shown in FIG. 4, floor panel 6 is monolithic, and comprises a flat base member 10, along the centre line of which a tubular, rectangular-section body 11 extends upwards. Base member 10 of floor panel 6 has two end skins 12 made of composite material fibre and separated to define in between a cavity 13 filled with soundproofing foam 14 or other soundproofing material. Floor panel 6 preferably comprises a number of through holes (not shown in detail) through which respective screws (not shown in detail) are inserted and fixed to central body 2.

Alternatively, floor panel 6 may be separate from or bolted to front body 5. In the latter case, floor panel 6 and front body 5 may be bolted together before being bolted to central body 2.

In a further embodiment, central body 2 may also comprise parts made of composite material fibre, or may be made entirely of composite material fibre.

Front body 5 and floor panel 6 provide for a high degree of crash and static and dynamic structural resistance, can be disassembled easily, are highly modular, and are cheap and easy to produce, even in relatively small numbers (up to 30 parts a day). 

1-15. (canceled)
 16. A car frame (1), the frame (1) comprising: a central body (2) comprising the passenger compartment of the car; a monolithic front body (5) connected to the central body (2) and made of composite material fibre; and a floor panel (6) connected to the central body (2); the frame (1) is characterized in that: the front body (5) is made of composite material fibre using RTM technology and is bolted to the central body (2); the floor panel (6) is monolithic, is made of composite material fibre using RTM technology, is bolted to the central body (2), and comprises a base member (10); the base member (10) of the floor panel (6) comprises two skin members (12) made of composite material fibre and separated to define a cavity (13) in between; and said cavity (13) defined between the two skin members (12) filled with soundproofing material (14).
 17. The frame (1) as claimed in claim 16, wherein the floor panel (6) is connected separately to the front body (5).
 18. The frame (1) as claimed in claim 16, wherein the floor panel (6) is bolted to the front body (5).
 19. The frame (1) as claimed in claim 18, wherein the floor panel (6) and the front body (5) are bolted to each other before being bolted to the central body (2).
 20. The frame (1) as claimed in claim 16, wherein substantially along the centre line of the base member (10) of the floor panel (6) extends upwards a tubular, rectangular-section body (11).
 21. The frame (1) as claimed in claim 16, wherein the floor panel (6) comprises a number of through holes through which respective fasteners are inserted and fixed to the central body (2).
 22. The frame (I) as claimed in claim 16, wherein the front body (5) comprises a front panel (7) positioned crosswise to the frame (1) and from which extend two lateral panels (8) positioned longitudinally with respect to the frame (1); said lateral panels (8) being positioned with their ends resting against the central body (2).
 23. The frame (1) as claimed in claim 22, wherein the central body (2) comprises a number of seats (9) into which the ends of respective end portions of the lateral panels (8) fit; and the end portions of the lateral panels (8) have a number of through holes through which respective fasteners are inserted and fixed to the central body (2).
 24. The frame (1) as claimed in claim 22, wherein the central body (2) comprises a number of metal parts (3, 4) welded to one another, and comprises a number of extruded, constant-section, straight bars (3) welded to one another at structural nodes defined by connecting bodies (4), each connecting body (4) comprising a number of pockets for housing the ends of corresponding straight bars (3), and said front body (5) being connected to two front connecting bodies (4) of the central body (2).
 25. The frame (1) as claimed in claim 24, wherein the central body (2) is made of aluminium.
 26. The frame (1) as claimed in claim 16, wherein the composite material fibre comprises a mixture of carbon or Kevlar fibre and glass fibre. 